The present invention relates to rotary engines, and more particularly, to an engine whose power is provided by rocket motors orbiting a central power shaft.
Through the Twentieth Century, the efficiencies and power to weight ratios of engines have improved steadily. Modern powerful aerospace gas turbine engines attain thermal efficiencies of 35% and a power to weight ratio of 3 to 4 kW per kg at a cost of $250 per kg. This high cost excludes these engines from the low power (under 500 kW) aircraft vehicular and industrial applications. For example, small airplanes and helicopters are powered only by prison engines to this day. The main factor contributing to this high cost is the complexity of a rotating turbine operating at high speed and high temperature. The main factor contributing to the low efficiency of low power turbine engines is the small dimension of the rotating compressors and turbines.
A major limitation of a rotating turbine is the creep characteristics of the turbine blade material. At present, the temperature limit at the turbine inlet of a gas turbine engine is 1500.degree. C. because of creep, although the combustion temperature is much higher (around 2500.degree. C.). This prevents turbine engines, especially small turbine engines, from approaching their theoretical thermodynamic efficiencies.
Thus, there is a widely recognized need for, and it would be highly advantageous to have, a low power rotary engine that would overcome these disadvantages of present known turbine engines.